Program

Talk information

Fabio Apruzzi "5d SCFTs: Graphs, Geometry and Gauge Theory"

5d superconformal field theories (SCFTs) can be realized as M-theory compactifications on singular non-compact Calabi-Yau threefolds. In this talk, I will exploit the relation between these Calabi-Yau threefolds and the elliptically fibered ones used to engineer 6d SCFTs in F-theory. Field-theoretically, this corresponds to 5d SCFTs descending from 6d N=(1,0) SCFTs by circle compactification and mass deformations. A very useful tool is provided by certain connected and weighted graphs, called Combined Fiber Diagrams (CFDs). They encode salient features of the partially resolved Calabi-Yau geometries, and provide a combinatorial way of characterizing all 5d SCFTs that descend from a given 6d theory. Remarkably, these graphs capture non-perturbative data of the 5d SCFTs, such as the superconformal flavor symmetry and BPS states, in a very manifest fashion. Moreover, many effective (quiver) gauge theory descriptions are determined from geometry, and their Coulomb branches graphically embed in the CFDs. I will present how this allows us to predict flavour symmetry enhancements at strong coupling, and, at higher rank, novel UV-dualities among quiver gauge theories.

Dongsu Bak "Traversable Wormholes and their Boundary Experimental Probes"

Hee-Joong Chung "BPS invariants for Seifert manifolds at rational level K"

It was conjectured that the Chern-Simons partition function or the Witten-Reshtikhin-Turaev invariant for closed 3-manifolds can be expressed in a particular form in terms of q-series with integer powers and integer coefficients. These q-series are new topological invariants, which are called the homological blocks. They can be interpreted as BPS invariants of 3d N=2 supersymmetric theories via the 3d-3d correspondence. In this talk, I will discuss the homological blocks for Seifert manifolds with gauge group G=SU(N) and the ones in the case of the rational Chern-Simons levels when G=SU(2).

Bartłomiej Czech "What does the Chern-Simons formulation of AdS3 gravity tell us about complexity?"

I will explain how to realize the wavefunction of a CFT2 ground state as a network of Wilson lines in the Chern-Simons formulation of AdS3 gravity. The position and shape of the network encode the scale at which the wavefunction is defined. The structure of the network is that of a Matrix Product State (MPS) whose constituent tensors effect the Operator Product Expansion. A general argument suggests identifying the "density of complexity" of this MPS network with the extrinsic curvature of the bulk cutoff surface, which by the Gauss-Bonnet theorem agrees with the Complexity = Volume proposal.

Chiung Hwang "Factorization, 3d Dualities, and Black Hole Entropy"

I will explain the factorization of 3d supersymmetric partition functions in the context of the Higgs branch localization, or more generally, of the holomorphic block. The factorization has proved a very useful tool for understanding strongly interacting quantum phenomena. In this talk, several applications to 3d dualities will be discussed with the use of the vortex partition function. In particular, it provides a proof of the Aharony duality for the superconformal index, whose analytic proof was absent for a long time, as far as we are aware. Furthermore, the factorization of the 3d superconformal index, combined with the Cardy limit, leads to the entropy of a rotating AdS4 black hole in the large N limit. It manifests the role of monopole operators to realize the N^{3/2} growth of the black hole entropy. The relations to other supersymmetric partition functions and black holes will be also discussed.

Finn Larsen "Statistical Mechanics of nearly Supersymmetric AdS Black Holes"

AdS black holes that are nearly supersymmetric depart from the strict limit in two distinct ways: a temperature may takes them above extremality and a potential may violate a certain constraint. We study these deformations and their interplay in classical gravity, the SYK model, and in N=4 SYM.

Ioannis Papadimitriou "Supersymmetric black hole thermodynamics and entropy extremization"

After reviewing the holographic version of I-extremization for static dyonic AdS4 black holes derived in arXiv:1712.01849, I will present a new superpotential for the general electrically charged BPS black holes with two equal angular momenta in N=2 gauged supergavity in five dimensions. I will then explain how this superpotential leads to a holographic version of I-extremization for AdS5 BPS black holes.

Sang-Jin Sin "Can we make a theory of strongly correlated system out of holographic duality? "

After describing Holographic Dirac materials, we discuss the result of transport calculation for most general quantum critical System described by “hyper scaling violating gravity.” If time allows I will talk about string spectrum and Heun’s equation.

Jaewon Song "Landscape of Simple SCFTs in 4d"

We explore the space of renormalization group flows that originate from N=1 supersymmetric gauge theory with one adjoint and a pair of fundamental chiral multiplets. By considering all possible relevant deformations - including coupling to gauge-singlet chiral multiplets - we find 34 fixed points for SU(2) theory in this simple setup. We observe that theories in this class exhibit many novel phenomena: emergent symmetry, decoupling of operators, and narrow distribution of central charges a/c. This set of theories includes the N=2 Argyres-Douglas theories and their mass deformed versions. In addition, we find a large number of candidate fixed point theories possessing unphysical fermionic operators -including one with central charges (a, c)≃ (0.20, 0.22) that are smaller than any known superconformal theory -that need further investigation.

Shigeki Sugimoto "2 dim QED and String Theory"

2 dim QED is an interesting strongly coupled quantum field theory. It has been studied for more than half a century and a lot of techniques have been developed. You may think that this theory is already explored completely and nothing new can be learned. But, in this talk, I will show you some new interesting results in 2 dim QED. One of the main results is that in 2 dim QED with Nf fermions of charge k, the axial symmetry is spontaneously broken from Z_{k Nf} to Z_{Nf}, and there are k degenerate vacua. I will also briefly explain that such a system can be realized in string theory and the techniques in 2 dim QED can be applied to study non-perturbative dynamics in string theory.